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Accuracy, stability, and corrective behavior in a visuomotor tracking task: a preliminary study.

Ryu YU, Buchanan JJ - PLoS ONE (2012)

Bottom Line: Differential accuracy and stability were found among the five tracking patterns with the 0° relative phase pattern being the most accurate and stable pattern.The amount of corrective movements decreased as the stability of tracking performance increased for the 0°, 45°, and 135° patterns.The results demonstrate that corrective behaviors are an important motor process in maintaining the stability of stable perception-action coordination patterns, while offering little benefit for unstable perception-action patterns.

View Article: PubMed Central - PubMed

Affiliation: Department of Physical Therapy, Catholic University of Daegu, Gyeongsan, South Korea. ryuyounguk@gmail.com

ABSTRACT
Visuomotor tracking tasks have been used to elucidate the underlying mechanisms that allow for the coordination of a movement to an environmental event. The main purpose of the present study was to examine the relationship between accuracy and stability of tracking performance and the amount of corrective movements that emerge for various coordination patterns in a unimanual visuomotor tracking task. Participants (N = 6) produced rhythmic elbow flexion-extension motions and were required to track an external sinusoidal signal at five different relative phases, 0°, 45°, 90°, 135°, and 180°. Differential accuracy and stability were found among the five tracking patterns with the 0° relative phase pattern being the most accurate and stable pattern. Corrective movements were correlated with changes in accuracy only for the 0° relative phase pattern, with more corrections emerging for less accurate performance. The amount of corrective movements decreased as the stability of tracking performance increased for the 0°, 45°, and 135° patterns. For the 90° and 180° tracking patterns, the amount of corrective movements was not correlated with pattern accuracy or pattern stability. The results demonstrate that corrective behaviors are an important motor process in maintaining the stability of stable perception-action coordination patterns, while offering little benefit for unstable perception-action patterns.

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An example power spectrum based from an FFT of the elbow's velocity signal.This example is from a single trial with a required relative phase of 0°. The three frequency regions are highlighted. The tracking frequency was 0.8 Hz. The high frequency component, representing the measure of intermittency, is highlighted with the red circles.
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pone-0038537-g002: An example power spectrum based from an FFT of the elbow's velocity signal.This example is from a single trial with a required relative phase of 0°. The three frequency regions are highlighted. The tracking frequency was 0.8 Hz. The high frequency component, representing the measure of intermittency, is highlighted with the red circles.

Mentions: A discrete Fourier transform was applied to the angular velocity time series with a Hanning window, and the resolution of power spectrum was 0.133 Hz. The resulting power spectrum was analyzed to determine the level of intermittency in each participant's performance. The power spectrum provided information about the distribution of power across the frequency components of a signal. The power spectrum also provided the frequency of the primary peak which was defined as the frequency at the largest power in the spectrum (Figure 2). The distribution of the power spectrum for each trial was normalized by the total power. From the normalized power spectrum three frequency components (low, main, and high) were defined (Figure 2). The main frequency component of the distribution was defined as ±0.133 Hz around the frequency of the primary peak. The high frequency component was defined as those frequencies above the main frequency component and the low frequency component was defined as the frequencies below the main frequency component. The high frequency component is the measure of intermittency with a larger proportion in the higher frequency range indicating more intermittent (corrective) performance during tracking. The low frequency component was not used for statistical analysis since it consisted of less than 1% of the total power distribution across all trials and was beyond the purpose of the present study.


Accuracy, stability, and corrective behavior in a visuomotor tracking task: a preliminary study.

Ryu YU, Buchanan JJ - PLoS ONE (2012)

An example power spectrum based from an FFT of the elbow's velocity signal.This example is from a single trial with a required relative phase of 0°. The three frequency regions are highlighted. The tracking frequency was 0.8 Hz. The high frequency component, representing the measure of intermittency, is highlighted with the red circles.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3366944&req=5

pone-0038537-g002: An example power spectrum based from an FFT of the elbow's velocity signal.This example is from a single trial with a required relative phase of 0°. The three frequency regions are highlighted. The tracking frequency was 0.8 Hz. The high frequency component, representing the measure of intermittency, is highlighted with the red circles.
Mentions: A discrete Fourier transform was applied to the angular velocity time series with a Hanning window, and the resolution of power spectrum was 0.133 Hz. The resulting power spectrum was analyzed to determine the level of intermittency in each participant's performance. The power spectrum provided information about the distribution of power across the frequency components of a signal. The power spectrum also provided the frequency of the primary peak which was defined as the frequency at the largest power in the spectrum (Figure 2). The distribution of the power spectrum for each trial was normalized by the total power. From the normalized power spectrum three frequency components (low, main, and high) were defined (Figure 2). The main frequency component of the distribution was defined as ±0.133 Hz around the frequency of the primary peak. The high frequency component was defined as those frequencies above the main frequency component and the low frequency component was defined as the frequencies below the main frequency component. The high frequency component is the measure of intermittency with a larger proportion in the higher frequency range indicating more intermittent (corrective) performance during tracking. The low frequency component was not used for statistical analysis since it consisted of less than 1% of the total power distribution across all trials and was beyond the purpose of the present study.

Bottom Line: Differential accuracy and stability were found among the five tracking patterns with the 0° relative phase pattern being the most accurate and stable pattern.The amount of corrective movements decreased as the stability of tracking performance increased for the 0°, 45°, and 135° patterns.The results demonstrate that corrective behaviors are an important motor process in maintaining the stability of stable perception-action coordination patterns, while offering little benefit for unstable perception-action patterns.

View Article: PubMed Central - PubMed

Affiliation: Department of Physical Therapy, Catholic University of Daegu, Gyeongsan, South Korea. ryuyounguk@gmail.com

ABSTRACT
Visuomotor tracking tasks have been used to elucidate the underlying mechanisms that allow for the coordination of a movement to an environmental event. The main purpose of the present study was to examine the relationship between accuracy and stability of tracking performance and the amount of corrective movements that emerge for various coordination patterns in a unimanual visuomotor tracking task. Participants (N = 6) produced rhythmic elbow flexion-extension motions and were required to track an external sinusoidal signal at five different relative phases, 0°, 45°, 90°, 135°, and 180°. Differential accuracy and stability were found among the five tracking patterns with the 0° relative phase pattern being the most accurate and stable pattern. Corrective movements were correlated with changes in accuracy only for the 0° relative phase pattern, with more corrections emerging for less accurate performance. The amount of corrective movements decreased as the stability of tracking performance increased for the 0°, 45°, and 135° patterns. For the 90° and 180° tracking patterns, the amount of corrective movements was not correlated with pattern accuracy or pattern stability. The results demonstrate that corrective behaviors are an important motor process in maintaining the stability of stable perception-action coordination patterns, while offering little benefit for unstable perception-action patterns.

Show MeSH